Fix handling of comments in newline-before-return

src/rules/newlineBeforeReturnRule.ts

@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import * as utils from "tsutils";
+import { getPreviousStatement } from "tsutils";
 import * as ts from "typescript";
 import * as Lint from "../index";
 
@@ -33,46 +33,51 @@ export class Rule extends Lint.Rules.AbstractRule {
  };
  /* tslint:enable:object-literal-sort-keys */
 
- public static FAILURE_STRING_FACTORY() {
- return "Missing blank line before return";
- };
+ public static FAILURE_STRING = "Missing blank line before return";
 
  public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
- return this.applyWithWalker(new NewlineBeforeReturnWalker(sourceFile, this.getOptions()));
+ return this.applyWithWalker(new NewlineBeforeReturnWalker(sourceFile, this.ruleName, undefined));
  }
 }
 
-class NewlineBeforeReturnWalker extends Lint.RuleWalker {
-
- public visitReturnStatement(node: ts.ReturnStatement) {
- super.visitReturnStatement(node);
-
- const parent = node.parent!;
- if (!utils.isBlockLike(parent)) {
-  // `node` is the only statement within this "block scope". No need to do any further validation.
-  return;
-  }
+class NewlineBeforeReturnWalker extends Lint.AbstractWalker<void> {
+ public walk(sourceFile: ts.SourceFile) {
+  const cb = (node: ts.Node): void => {
+  if (node.kind === ts.SyntaxKind.ReturnStatement) {
+ this.visitReturnStatement(node as ts.ReturnStatement);
+  }
+  return ts.forEachChild(node, cb);
+ };
+ return ts.forEachChild(sourceFile, cb);
+ }
 
- const index = parent.statements.indexOf(node as ts.Statement);
- if (index === 0) {
- // First element in the block so no need to check for the blank line.
+ private visitReturnStatement(node: ts.ReturnStatement) {
+ const prev = getPreviousStatement(node);
+ if (prev === undefined) {
+ // return is not within a block (e.g. the only child of an IfStatement) or the first statement of the block
+ // no need to check for preceding newline
  return;
  }
 
- let start = node.getStart();
- const comments = ts.getLeadingCommentRanges(this.getSourceFile().text, node.getFullStart());
+ let start = node.getStart(this.sourceFile);
+ let line = ts.getLineAndCharacterOfPosition(this.sourceFile, start).line;
+ const comments = ts.getLeadingCommentRanges(this.sourceFile.text, node.pos);
  if (comments) {
- // In case the return statement is preceded by a comment, we use comments start as the starting position
- start = comments[0].pos;
+ // check for blank lines between comments
+ for (let i = comments.length - 1; i >= 0; --i) {
+ const endLine = ts.getLineAndCharacterOfPosition(this.sourceFile, comments[i].end).line;
+ if (endLine < line - 1) {
+ return;
+ }
+ start = comments[i].pos;
+ line = ts.getLineAndCharacterOfPosition(this.sourceFile, start).line;
+ }
  }
- const lc = this.getLineAndCharacterOfPosition(start);
-
- const prev = parent.statements[index - 1];
- const prevLine = this.getLineAndCharacterOfPosition(prev.getEnd()).line;
+ const prevLine = ts.getLineAndCharacterOfPosition(this.sourceFile, prev.end).line;
 
- if (prevLine >= lc.line - 1) {
+ if (prevLine >= line - 1) {
  // Previous statement is on the same or previous line
- this.addFailureFromStartToEnd(start, start, Rule.FAILURE_STRING_FACTORY());
+ this.addFailure(start, start, Rule.FAILURE_STRING);
  }
  }
 }

test/rules/newline-before-return/default/test.ts.lint

@@ -87,4 +87,28 @@ function foo() {
  return;
 }
 
+function test() {
+ console.log("Any statement");
+ // Any comment
+
+ return;
+}
+
+function foo() {
+ fn();
+ // comment
+
+ // comment
+ return;
+}
+
+function bar() {
+ "some statement";
+ //comment
+ ~nil [0]
+ //comment
+ //comment
+ return;
+}
+
 [0]: Missing blank line before return